The present invention relates to locking and security devices which may be used to secure one or more objects together. In applications requiring the use of the present invention, it is highly essential that the rod be securely locked against accidental or inadvertent removal or displacement, yet be readily removable when desired. General applications for a locking rod of the present invention would include the telescopic locking of trailer towing draw bars to their female vehicle-mounted receiver boxes, or to lock one object to another object such as the bow of a boat or jet ski to the bow ring of a trailer, or for securing attachments and accessories such as bicycle carriers into all types of vehicle-mounted receiver-type receptacles.
Prior proposals (see U.S. Pat. No. 4,711,106 and U.S. Pat. No. 4,428,211) offer types of locking devices designed for securing attachments and accessories to vehicles. These devices require the user to be burdened with carrying additional tools, such as a key, in order to remove the locking device. The prior proposals fail to provide the user with a simple, reliable, and convenient way of removing the locking device without also having a specialized tool or key to facilitate its removal. The prior proposals' drawbacks become apparent in practical applications such as their use on construction vehicles used by numerous employees and that may be required to pull a multitude of different equipment, which may each require a different hitch tongue and ball assembly. Under this scenario, the requirement of having a specialized tool or key carried by each employee becomes increasingly burdensome, or without multiple keys, greatly increases the risk of a single key being lost at a muddy construction site or being broken off in the lock device itself. Further, the requirement of a specialized tool or key requires the physical transportation of that specialized tool or key to specific locations versus the convenience of verbal communication of a combination locking number via telephone, facsimile, or an electronic pager. In recreational applications such as boating or water sports wherein multiple family members and/or friends may use or borrow a certain water craft, the same logistic problems of requiring a specialized tool or key would exist. Further amplifying the inconvenience of carrying a specialized tool or key to lock or unlock a given piece of equipment, is that the types of clothing being worn, such as swimming suits, are often not equipped with reliable area for securely stowing a specialized tool or key. The fact that these vehicles are operated in water of substantial depth greatly increases the opportunity of permanent loss of the specialized tool or key should it be accidentally dropped. Further, these prior proposals fail to provide a locking device that is simple in construction, inexpensive to manufacture, highly effective in operation, and sleek in appearance. While still other known prior art make attempts at utilizing combination locking devices (see U.S. Pat. No. 4,445,348), they fail to provide the user with the structual rigidity needed to serve effectively as a cross bolt, or shear pin locking device. Prior proposals further fail to provide structurally sound means permitting the ready change of the lock combination to one easy for the user to remember. The invention eliminates these and other drawbacks of the prior art.